Kingdom [Animalia] Linnaeus, 1758 - animals
   Subkingdom Metazoa Haeckel, 1874 see Kingdom Animalia Linnaeus, 1758
     Division Eumetazoa Butschli, 1910 see Subkingdom Eumetazoa Butschli, 1910
       Subdivision Bilateralia
         Phylum Pentacoela
           Subphylum Branchiotremata
             Class Pterobranchia Lankester, 1877 - pterobranchs
               1 Family Cephalodiscidae Schimkewitsch, 1893
               2 Family Atubariidae Benito, 1982 see Family Atubaridae Benito, 1982
               3 Family Rhabdopleuridae Harmer, 1905